1. Technical Field
The disclosure relates to an antenna module, and more particularly to a broadband and multi-band antenna module having a stable radiation pattern.
2. Related Art
To connect to wireless local area network, a computer device must be electrically connected to a radio transceiver device. An electrical connection portion of the radio transceiver device generally meets the standard specification of a Universal Serial Bus (USB), and can be electrically connected to a USB port of the computer device. Therefore, at least one antenna module for receiving and transmitting radio signals needs to be built in the radio transceiver device, and preferably, the antenna module is a broadband and multi-band antenna module. However, as communication apparatuses become lighter, thinner, shorter, and smaller, the size of the antenna module also needs to be gradually reduced, resulting in the incapability of optimizing the performance of the antenna module. In order to solve the above problem, in the prior art, multiple antennas must be arranged in a communication apparatus with limited volume, which is difficult to design. Alternatively, the antenna module is manufactured outside the communication apparatus, which largely increases the volume of the radio transceiver device and does not meet the light and thin requirements of the modern communication apparatus.
On the contrary, to install the antenna module in a miniature communication apparatus and maintain the antenna performance as well, the volume of the antenna module must be limited to a certain size, and thus the operation band of the antenna module is limited, or a radiation pattern of poor stability is caused. Therefore, to design a broadband and multi-band antenna module having an omnidirectional and stable radiation pattern is one of the schemes for developing an antenna module built in a miniature communication apparatus.